Serena Williams US Open
Serena Williams celebrates her US Open semifinal win over Ekaterina MakarovaReuters

Serena Williams vowed to get back into her Grand Slam groove after shock exits at the Australian Open, French Open and Wimbledon, and the American title-winning machine has stayed true to her word, banishing Ekaterina Makarova in straight, breezy, easy-peasy sets to setup a US Open final showdown with a tennis player with plenty to prove as well – Caroline Wozniacki.

The world number one was left reeling after being knocked out in the third round at Wimbledon, which followed her fourth round and second round exits in the first two Grand Slams of the year, but in the more familiar confines of New York, the usually unstoppable 32-year-old has looked more like her old self, brushing aside any competition, using those powerful groundstrokes, and impeccable ability to hit one punishing winner after another to glide all the way to the final.

"I'm just really excited to be in the final," said Williams. "In the beginning of the week I definitely wasn't sure I would make it this long. Definitely wasn't sure I'd be here. So I'm just elated, to be honest, to have made it this far."

On Friday, Makarova, the No.17 seed, was the hurdle to cross for Williams, and the moment that yellow tennis ball struck the American's racket sweetly for the first time, there was only ever going to be one winner, as Serena rolled to a 6-1, 6-3 win in exactly one hour.

Makarova, after the match, admitted even she didn't expect Williams to come out and be as aggressive as she was in the semifinal. "Serena, she's a great, unbelievable player," said the Russian. "It's always tough to play against her.

"She was so aggressive. I don't know, maybe I didn't think that she will be that aggressive. Like she's just coming, you know, so early, so sometimes I was too late because she was too fast. I don't know. I'm still so happy that I was in semis."

While Makarova can now look forward to the women's doubles final, which she will play on Saturday, with a sense of satisfaction having reached the final four of the US Open, Williams, the defending champion, will know her job is not done quite yet, with one more obstacle, in the shape of Wozniacki, lying in wait.

Caroline Wozniacki US Open
Caroline Wozniacki is a picture of happiness after her victory over Shuai Peng in the US Open semifinalReuters

Wozniacki has looked as good as she has done for quite a while in a Grand Slam, highlighted by the epic victory over Maria Sharapova in the fourth round.

Standing in her way of a US Open final on Friday was Shuai Peng, so impressive so far, and after a tough first set, which Wozniacki won 7-6 (1) in the tie-breaker, it all went horribly wrong for the Chinese, with illness ending all hopes of a comeback.

Peng was forced to retire with the match at 7-6, 4-3 in Wozniacki's favour as the heat got the better of the first-time Grand Slam semifinalist.

"It was really hard to watch for me whenever I saw her collapse on the court," said the gracious Wozniacki of Peng's struggles. "You know, tennis is great, but the health is more important. To see her struggling out there, I just wanted to make sure she was OK.

"I got the word that she's OK now and just getting cooled down, so that's great to hear. I'm in the final, which is obviously great. It's been five years for me since my last one here, so I'm extremely happy to be back there."

In that final, in the 2009 US Open, Wozniacki was topped by Kim Clijsters in straight sets. The Dane will certainly hope for a different result this time around.